Pivoted tube bender with tube positioning mark and adjustable tube locating device



March 18, 1958 E. A. DE voss 2,327,101

PIVOTED TUBE BENDER WITH TUBE POSITIQNING MARK AND ADJUSTABLE TUBELOCATING DEVICE 3 Sheets-Sheet 1 Filed 001:. 4, 1954 March 18, 1958 E.A. DE voss 2,827,

PIVOTED TUBE BENDER WITH TUBE POSITIONING MARK AND ADJUSTABLE TpBELOCATING DEVICE Filed Oct. 4, 1954 3 Sheets-Sheet 2 March 18, 1958 E. A.DE voss 1 2,

PIVOTED TUBE BENDER WITH TUBE POSITIONING MARK AND V ADJUSTABLE TUBELOCATING DEVICE Filed Oct. 4. 1954 5 Sheets-Sheet 3 IlllllH 'be made ina tube.

ilnited States Patent PIVO'iED BENDER WETH TUBE POSITION- ING MARK AbllADFUSTABLE TUBE LO CATING DEVIQE Edwin A. de Voss, Los Angeles, Calif,assignor to Northrop Aircraft, End, l-lawthome, Calif., a corporation ofCalifornia Application @ctober 4, 15 54, Serial No. 459,990

3 Claims. (Cl. 153-46) The present invention relates to tube bendingapparatus and more particularly to a tube bending machine including atube positioning facility, the use of the latter being made possible bythe novel construction and arrangement of the component parts of themachine.

Tube assemblies, comprising one or more lengths of bent or preshapedtubes, are well known and extensively utilized for conveying fluidbetween various parts of a machine which are responsive to fluidpressures. A modern aircraft constitutes a typical example in whichnumerous preshaped tube assemblies function in the aforementionedcapacity. Such bent or preshaped tubes are normally fabricated with theaid of an automatic or a hand bending machine depending on the numberrequired. Either of the above machines has objectional featuresrendering them unsatisfactory for certain bending operations. Forexample, if a small number of preshaped tubes is required, the timerequired to set up an automatic machine will undoubtedly exceed the timerequired to bend the same number of tubes with a hand machine. it isalso obvious that regardless of the number of preshaped tubes requiredforming them on a hand operated machine constitutes a time consumingoperation. Therefore, the need for a tube bending machine enablingeither large or small quantities of tubes to be shaped accurately andexpeditiously is quite apparent.

The present invention discloses a tube bending machine in which thebending operation and the movement of the respective parts thereof arereversed as compared with the procedure and movement of parts inconventional tube bending machines. Briefly the present inventionemploys a stationmy radial block and a movable slide block. Employing amovable slide block results in a previously executed bend maintaining afixed relationship, with respect to stationary portions of the machine,while a subsequent bend is being executed. Accordingly a fixture of thetype disclosed. herein may be secured to the stationary portions of themachine to' facilitate the location, plane, and degree of all bends toThe specific manner in which the instant tube bending machine operates,also the manner in which the locating fixture cooperates with the tubebending facility, will become more apparent as the disclosureprogresses.

Accordingly it is an object of the instant invention to provide a tubebending machine in which small quantities of preshaped tubes ofidentical configuration may be fabricated accurately and expeditiously.

Another object is to provide a tube bending machine in which previouslybent portions of a tube will maintain a fixed relationship with respectto non-movable portions of the machine during a subsequent bendingoperation.

Another object is to provide a tube bending machine incorporating meanswhereby the location, plane, and degree of bends to be made in a tubeare readily locatable.

These and other objects will become more apparent from the followingdescription and drawings in which like reference characters denote likeparts throughout the several views. t is to be expressly understood,however, that the drawings are for the purpose of illustration only andnot a definition of the limits of the invention, reference being had forthis purpose to the appended claims.

ln the drawings:

Figure l is a perspective view of the tube bending machine of theinstant invention.

Figure 2 is a detailed perspective view of certain parts of the tubebending machine shown in Figure 1.

Figure 3 is a fragmentary elevational view of the tube bending machineviewed as indicated by the arrow 3 in Figure 2, this view in particularshows the hand wheel of the instant invention and associated parts.

Figure 4 is a cross-sectional view of the tube bending machine as viewedalong the line of Figure 2.

Figures 5 and 6 are plan and elevational views, respectively, of thetube bending assembly of the instant invention.

Figure 7 is a cross-sectional view of one of the connectors of the tubelocating assembly as viewed along the line 77 of Figure 2.

Figure 8 is a perspective view of a length of tubing to be fabricated.

Figures 9 and 9a are perspective and elevational views, respectively, ofa presnaped tube.

Figure 10 is an elevational view of the tube bending assembly showingthe preshaped tube of Figures 9 and 9a in a typical locating position.

Figures ll and 12 are elevational views bending assembly showing variouspositions the component parts thereof in forming a configuration shownin Figures 9 and 9a.

Figure 13 is an exploded perspective view of the tube locating member ofthe instant invention.

Referring to the drawings, Figure 1 shows a complete tube bendingmachine 11 of the type disclosed herein. Principal component parts ofthe machine include a tube bending assembly 12 and tube locatingassembly 14 each mounted on a common supporting structure 15. Thesupporting structure, in the present embodiment, consists of a bed plate17 supported at a suitable height by a channel member 18 and legs 19. Afolding leaf or shelf 21 is also provided on which tubes to be or thathave been fabricated may be supported. Mounted on the upper surface ofthe bed plate is a guide rail .3. on which the assembly 14 is mountedfor longitudinal movement thereof with respect to the guide rail and bedplate. The bed plate extends beyond one end of the channel member 13 toprovide a suitable support for the tube bending assembly 12.

Referring to Figures 2, 3, 5, and 6 it is seen that the tube bendingassembly 12 consists of a supporting shaft 23 having a disk-like radialblock 24 fixedl' secured thereto at its upper end as viewed in Figure 2.A major peripheral portion of the radial block is provided with acontinuous tube receiving groove 2%, the latter being semi-circular incross-section. A major portion of the groove 2%) is of arcuateconfiguration so that similar wall portions thereof are spaced equalradial distances from the axis of the shaft 23. The groove 2%)terminates at one end in a straight portion which cooperates with aclamp block 32 to be described presently. A reference mark 39 extendsnormal to the periphery of the block 24 at the point at which thearcuate portion of the groove 24) becomes tangent to the straightportion thereof.

The shaft 23 is mounted in a vertical attitude on the overhangingportion of the bed plate by means of a sleeve 26 fixedly secured to thebed plate. Angular movement of the shaft 23 is prevented by aconventional of the tube assumed by tube of the section. ncut on the,armld between a first position in which the walls of the groove 33cooperate with the straight portion :of the groove 29 to firmly hold alength of-tub- V tending radially from the axis of the shaft 23.

keyjindLlreywayfassociated with the shaft and sleeve, however, the shaftmay be raisedor loweredas desired and held in any suitable verticalposition by a hand screw 27.

:Mounted' on and extending from the shaft 23, at a .position'intern'lediate the plate 1'7 andthe radial block .24, 'an arm 28. Theportion of thearm 2d encom- Passingthe shaft Z3 is bifurcated to allowan adjustable stopmember to be mounted on: the shaft between therespective forks o'f the arm 28. The arm Eb nfixedly secured to theshaft 23'by means of conventional set screws or the like. The-stopmemberZ? is mounted for august movement on the shaft 23 and 'inay besecured thereto inany desired pos ition by sham screw 3:1. The functionof the stop member 29will become more apparent as the vdisclosureprogresses. Mounted on the arm 28 is a clamp block 32- provided with astraight tube receiving groove 33 which is also semi-circular in cross-The block 32 is mounted for pivotal move irig therebetween and asecondposition in which :the

tubing may be frec ly removed from the grooves and 33. The block 32 ismanually moved between the two positions described above a lever 34,also pivotally mounted on the m 28, acting iii-conjunction with an ofthe shaft 23 and along the aforementioned longitudif.

nal axis of the arm 37. The member 39h; moved by means of a manuallyoperable lever 4? pivotally mounted on-the :arm 37 and'by a cooperatingtoggle type linlrage 5 1. ,A1 1 --elorrgated holding member 33 isfixedly. se-

cared to the member 39. A groove 43 having a rectangular cross-sectionis formed in the member 38. .The' groove 43 is further characterized inthat the side walls thereof are normal to the aforementioned axis A A ofthe arm 37. The groove 43 is adapted to slidably receive an elongatedslide block 42 which is also rectangular in cross-section. V v

In the assembled position ofthe various parts of the assembly 12, asbest seen in Figure 2, the following relationships are found. I Theelongated side of the block 42, opposing the block 24, is provided witha straight tube receiving groove 44 which is semi-circular incrosssection; A groove 46 is also provided in the :.side of the block 42opposite the side containing the groove .44. Also pivotally mounted onthe member 39, by means cumferential groove 48 formed in its outerperipheral surface. Accordingly it will be apparent that the axes of thegrooves 44 and 46 will-also be normal to the aforementioned axis A-A ofthe arm 37 regardless of 23. The axes of the semi-cylindrical grooves20, 33, and 44 are located in a common horizontal plane. Portions of theouter peripheral surface of the roller 47 are in firm contact withportions of the side of the block '42 containing thegroove 46 At suchtimes as the' member 39 is moved to a position most adjacent block 24,the roller 47 and block 24 will bear tangentially on the block 42v atdirectly opposite positions. In other words a plane containing the axesofthe shaft 23 and roller 47 willalso contain, the-points of tangency ofblock 24 and roller 47 with the:slide, bloek-42. The position of:t'he'arm 37 and block 42,'with':respect to the blocks i of a pin 54, isa hollow roller element 47 having a ciri T the latters angular positionwith respect to the shaft" 78, and a flexible diaphragm 79.

24 and 32,'as best seen in Figures 2 and 10, constitutes the initialposition which these parts are'caused toassurne prior to a bendingoperation. One end of the block 32 is chamfered as indicated at 52 toprovide clearance for the roller 47 to assume its initial position asdescribed above. f 7

With a length of tubing held in the grooves Ziland 33a, andwiththetubing firmly bottomed in the gro'ove stressed spiral spring53positioned in the hollo'ivf portion Iof the roller 4'7 as shown in Figlfe l0. Onefendlof the s pring 53isfattached to the pin :54, aboutwhichthe roller 47 rotates, its other end is secured to'thelinnerperiphery of the disk 47. One end of a flexibleinietal cable 56 isattached to the periphery of the roller .37 and the oth er end isattached to the side of'the; block 42in which the groove 46 is formed sothat intermediate portions thereof .are located .in the grooves '46 and.48..

The roller 47, spring 53, and cable 56 cooperate tome turn the bloc:'42'to its initial relative'positio'nin the holder 3 3'upon completionof a bending operation' 'and the releasing of the block 42 from thetubing. ,;-Return movement of the block 42 is arrested byfa pro ect lugstop (not shown) formed on the holder 38. Itis apparent that the grooves46 and lfi mate with each other to provide clearance'for the cable es.

H A hand wheel '57, having an annular V-sliapedgr oove 69, is mountedfor free angular movement on thei'vshaft 23. The hand wheel rests on theupper surface of t lie plate 17' and serves to move 'a cable 68 therebyshifting a connector 58 ofthe tube locating assembly 14in a mannerpresently explained in connection with the detailed description ofitheassembly 14.

In the present embodiment the tube locating assembly I 14 includes threefluid operated ball and socket connectors 58, Y59, and 61. The connector58 is slidably secured to aspire forlongitudinal movement thereon, theother two connectors are supported by the connector 58 on rigid arms 62and 63. The connector 58 includes a base portion provided With'a groove66 adapted to m- ,ceive the guide rail 22 as seen in Figure 4. Tofacilitate ihe aforementioned longitudinal movement of the connectorf SSa cable68 is rigged to operate in the groov d) 7 of the handwheel'57 andthrough a pulley 69, thelatter being attached toithe end of the plate 17opposite the ass embly 1 2. The ends of the cable .22are attachedito.opposite sidesof the-base portion of the connector 58. With the cablerigged as described above it will ,be apparent'that the connector 58responds to rotary movements of the hand 'whee1 57. A conventionallocking 'device 67 is provided in the base portion of the connector Thislocking device allows or arrests longitudinal ,movement of theconnector58.as desired by an'oper'ator of the machine :11.

The aforementioned connectors are of substantiallyidenticalconstruction. Accordingly a description of the connector 61follows which will also be applicable to thefconnectors 58 and.59.' Theconnector 61 comprises a disk-like closure element 73, retainer andauxiliaryretainer elements 74 and 76, respectively, a ring element.component parts of the connector 61 are assembled as shown'in Fig ure 7with the spherical end of the 7 1 contained betweenspherical surfaceportions ofelernents 74 and 7,6. Fluid at superatmospheric.pressureisuti- The above recited lized to render the spherical end ofthe arm 71 nonmovable with respect to the elements 74 and 76. Theaforementioned fluid enters the connector 61 through the elbow 81 andcommunicates with the side of the diaphragm 79 opposite the element 76.At such times as fluid at superatmospheric pressure is not in contactwith the diaphragm 79 the arm 71 may be manually adjusted as desired.During these latter periods the spherical end of the arm 71 is firmlybut adjustably held between the spherical surface portions of theelement 74 and a supporting element 83 by a precompressed helical spring82. The spring 82 is selected so that the force exerted thereby allowsthe arm 71 to be manually adjusted but retains it in any desiredposition. A snug sliding fit between the mating cylindrical walls of theelement 74 and 76, the action of the spring 32, and the configuration ofthe element 83 preclude any lateral movement of the ball in the element74 at such times as fluid is not present in the connector. The upper endof the element 83 is provided with a concave surface which mates withthe spherical end surface of the arm 71. The lower portion of theelement 83 comprises a cylindrical shell the outer surface of whichbears a snug sliding relationship with a counterbore 85 formed in thebase of the element 76.

Referring again to Figure 2 it is apparent that the spherical endportion of the arm 62 is contained in the connector 58 while the otherend of the arm is rigidly attached to the connector 59 as indicated at7'7. Similarly the arm 63 is associated with the connectors 59 and 61.Attached to the free end of the arm member 71 is a tube locating member72 to be presently described. A flexible conduit 84 provides a passagefor fluid between a source of fluid at superatmospheric pressure (notshown) and the connectors 53, 59, and 61. The flow of fluid to and fromthe above connectors is controlled by a valve mechanism 86 located inthe conduit 84.

The tube locating member 72 consists of a pair of elongated bar members87 and 83 of similar configuration hinged together at respective ends topermit relative angular movement therebetween.

The elongated bar members may be hinged together by means of a tongue102, formed in an end of the member 88, and a tongue receiving slot 193,formed in an end of the member 87, and defined by side portions libiand1% of the latter member. In the assembled position of the members 87 and88 the side surfaces defining the slot 103 provide a snug sliding fitfor the tongue 1%2. Also in the assembled position of the members 87 and83 a bolt-like element 91 extends through registering apertures in theportions 104, 196, and tongue 192 and engages mating threads in theportion 1436. Upon suificient engagement of the aforementioned threads ashoulder M7, formed on the element 91, bears against the upper surfaceof the portion 104 thereby rendering the members 87 and 88 immovablewith respect to each other. Rotary movement is imparted to the element91 by means of a radially extending handle 198. In view of the abovediscussion it will be apparent that the element 91 provides meanswhereby the members 37 and 33 may be freed for relative angular movementor rendered immovable with respect to each other in any desired angularrelationship with a predetermined range.

The member 87 is fixedly secured at its mid-portion to the free end ofthe tube 71 as by welding or the like. A pair of spaced quarter circularparallel grooves 85 and 89 extend longitudinally of the member 87. Apair of identical grooves 99 and 95 are similarly formed in the member88. The location of the grooves 85 and 90, in the assembled position ofthe members 37 and 38, respectively, is further characterized in thatthe axes of these grooves are located in a common plane. Similarly theaxes of the grooves 89 and 95 are also located in a common plane. Thehinged connection between the members 87 and 88 permits angularmovementthereof between a first position in which the axes of thegrooves and 90 coincide with a straight line and a second position inwhich the included angle between their axes constitutes an acute angle.The radius of the grooves 35, 89, 90, and is substantially equal tothe'outside radius of a tube being shaped in the machine 11.

The component parts of a preferred embodiment of the instant inventionhaving been described a more complete understanding of its novelfeatures and advantages will be forthcoming from the followingdescription of its operation.

For illustrative purposes it may be assumed that a straight length oftubing 1% is to be fabricated to conform with the performed tube 92 asshown in Figures 9 and 9a. The tube 92 includes three typical bends 93,94, and 96, straight portions 97 and 93, and end portions $9 and 101.The radius of each of the bends in the tube n2 is equal and is furthercharacterized in that the bend 93 is located in a first plane while thebends 94 and 9 5 are located in a second plane positioned at ninetydegrees (90) with respect to the first plane.

Inasmuch as the procedure involved in the executing each of the bends93, 94, and @6 is substantially the same only the operations ineffecting the bend 94- will be described in detail. The preformed tube92 is first utilized to locate the member 72 in a position correspondingto the bend To accomplish this the tube 92 is positioned in the assemblylit with the bend 93 thereof located to the left of the radial block 2as shown in Figure 10. The tube 92 is located in the position shown bypositioning the point of tangency of the bend with the straight portion97 directly opposite the reference mark 3% at such time as the bend 9dis bottomed in the arcuate portion of the groove 26. The tube 92 is nowsecured in the above position by the blocks and 32. With the tube 92thus secured in the assembly 12 the bend 93 will be positioned in avertical plane with the end portion 9 extending downwardly. The assembly14 is new adjusted so that the straight portions and 99 of the tube 92are bottomed in the grooves and b d, or 85? and 95, respectively, of themember assembly is now rendered immovable by means of the loc ting evicea? and by causing presse d fluid to communicate with each of theconnectors 59, and 63.. The members 37 and 33 are also looked inposition by means of the locking device 91. The stop mem ber 29 is alsoset at this time to govern the extent of the bend 94. To accomplish thisthe side block 42 is urged into contacting relationship with the tube 92and the arm 37 rotated in a clockwise direction until the straightportion i=3 of the tube 92 is bottomed in the groove 44 of the block 12. The stop member 2? is now moved into abutting relationship with thearm 37 and secured in this position by means of the hand screw 31. Thetube 92 is now removed from the assembly 12.

The tube 1% to be fabricated is now positioned in the assembly 12.

it is understood that a bend in the tube 1%, identical to the bend 93 ofthe tube 92, has been efiected during a previous operation. Accordinglythe strai ht portions of the tube ltltl, corresponding to the pertions97 and 99 of the tub 92, are bottomed in the grooves 85 and 9i? or 39and @5, respectively, with the straight portion 99 extending verticallydownward. At this time the straight portion of the tube 1%, correspondinto the portion W of the tube 92, is bottomed in the straight portion ofthe groove 21?. This procedure locates the tube 1% in the properposition so that the bend 94 may be executed. The tube M39 is nowsecured between the bloclrs 24 and 32, the slide block urged into firmcontacting relationship with the tube, and the arm 37 rotated in aclockwise direction until it contacts the stop 2%. The bend in the tube36%, corresponding to the bend 94 in the tube 2, has thus been effected.Any number of identical bends may now be made in tubes "During the aboveoperation it shouldbe noted that the presha'ped portion'of the'tube I00remainsffixetl while 'th'e straight portion-of the tube is moved i-nresponse to movem'ents of the :slide block 42. ln conventional equipmentthe reverse procedure is followed, that is the pre's'ha'ped portions ofa tube be'ing fabricated are-moved While the 'untabr-icated portionaemains s'tatiouary or moves longitudinally. It should be apparent thatthe assenihly .14 enables a tube to b: positioned in the :as-

sembly 12 so that the longitudinal location and'nla'n'e of a 'bend to bemade in' the tub'e 'will :fbe automatically de- "te'r mined. The degreeof beniiji'sdeterminetl by thezbesition 'of'the stop 29withrespecttothearm 3 7.

Figures 1 1 a'nd L2 show the relative positions uihich certain parts-"ofthe assemblies I- Z an'cl assume at the completion of the bends 94 a'rfd96. 'These views are believed to be self explanatory Rand -furtherexplanation not'deemed necessary. j

While "in order 'to c'omplywith the statute,the irivention has beendescribed in' language more orlle'ss ispecificfas to structuralfeatures, it is to -be uniierstood that the invention is not limited tothe specific feature's shown,

but that the means a'nd construction 'herein'idiselosed comprisea'preferred form er putting the invention into effect, and the inventionis therefore claimedain any of,

' radial block; a tube positioning mark #on a silielface of said radialblock intersectin'g said varcuate edge portion; anlongated tubelocating'device, which may-be rendered either flexible or rigid, one end-ofwhich issecure'd'to said base structure; a pair of adjustablemlongatedmempassing throughsaid r ihin gedr endjportions and haying tarestingzrelative aangular movement, grespectively, -;betvy.een

3.,Apparatus as set forth in=claim12 furthergcharacterized in that :saidcomplementary tube .-receiviug grooves consist of :-;at least one tube,:receiving 4 groove; having a partial .cylindricalisurface,stormed ineach; of said elontgated memberswith the axes-thereof;lyingeinzavcommenplane. l r

Referencs,Citedinithe tile ofithisslpatent r

